lib/ext2fs/get_pathname.c

   1 /*
   2  * get_pathname.c --- do directory/inode -> name translation
   3  *
   4  * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 /*
  13  *
  14  *      ext2fs_get_pathname(fs, dir, ino, name)
  15  *
  16  *      This function translates takes two inode numbers into a
  17  *      string, placing the result in <name>.  <dir> is the containing
  18  *      directory inode, and <ino> is the inode number itself.  If
  19  *      <ino> is zero, then ext2fs_get_pathname will return pathname
  20  *      of the the directory <dir>.
  21  *
  22  */
  23
  24 #include "config.h"
  25 #include <stdio.h>
  26 #include <string.h>
  27 #if HAVE_UNISTD_H
  28 #include <unistd.h>
  29 #endif
  30
  31 #include "ext2_fs.h"
  32 #include "ext2fs.h"
  33
  34 struct get_pathname_struct {
  35         ext2_ino_t      search_ino;
  36         ext2_ino_t      parent;
  37         char            *name;
  38         errcode_t       errcode;
  39 };
  40
  41 #ifdef __TURBOC__
  42  #pragma argsused
  43 #endif
  44 static int get_pathname_proc(struct ext2_dir_entry *dirent,
  45                              int        offset EXT2FS_ATTR((unused)),
  46                              int        blocksize EXT2FS_ATTR((unused)),
  47                              char       *buf EXT2FS_ATTR((unused)),
  48                              void       *priv_data)
  49 {
  50         struct get_pathname_struct      *gp;
  51         errcode_t                       retval;
  52         int name_len = ext2fs_dirent_name_len(dirent);
  53
  54         gp = (struct get_pathname_struct *) priv_data;
  55
  56         if ((name_len == 2) && !strncmp(dirent->name, "..", 2))
  57                 gp->parent = dirent->inode;
  58         if (dirent->inode == gp->search_ino) {
  59                 retval = ext2fs_get_mem(name_len + 1, &gp->name);
  60                 if (retval) {
  61                         gp->errcode = retval;
  62                         return DIRENT_ABORT;
  63                 }
  64                 strncpy(gp->name, dirent->name, name_len);
  65                 gp->name[name_len] = '\0';
  66                 return DIRENT_ABORT;
  67         }
  68         return 0;
  69 }
  70
  71 static errcode_t ext2fs_get_pathname_int(ext2_filsys fs, ext2_ino_t dir,
  72                                          ext2_ino_t ino, int maxdepth,
  73                                          char *buf, char **name)
  74 {
  75         struct get_pathname_struct gp;
  76         char    *parent_name = 0, *ret;
  77         errcode_t       retval;
  78
  79         if (dir == ino) {
  80                 retval = ext2fs_get_mem(2, name);
  81                 if (retval)
  82                         return retval;
  83                 strcpy(*name, (dir == EXT2_ROOT_INO) ? "/" : ".");
  84                 return 0;
  85         }
  86
  87         if (!dir || (maxdepth < 0)) {
  88                 retval = ext2fs_get_mem(4, name);
  89                 if (retval)
  90                         return retval;
  91                 strcpy(*name, "...");
  92                 return 0;
  93         }
  94
  95         gp.search_ino = ino;
  96         gp.parent = 0;
  97         gp.name = 0;
  98         gp.errcode = 0;
  99
 100         retval = ext2fs_dir_iterate(fs, dir, 0, buf, get_pathname_proc, &gp);
 101         if (retval == EXT2_ET_NO_DIRECTORY) {
 102                 char tmp[32];
 103
 104                 if (ino)
 105                         snprintf(tmp, sizeof(tmp), "<%u>/<%u>", dir, ino);
 106                 else
 107                         snprintf(tmp, sizeof(tmp), "<%u>", dir);
 108                 retval = ext2fs_get_mem(strlen(tmp)+1, name);
 109                 if (retval)
 110                         goto cleanup;
 111                 strcpy(*name, tmp);
 112                 return 0;
 113         } else if (retval)
 114                 goto cleanup;
 115         if (gp.errcode) {
 116                 retval = gp.errcode;
 117                 goto cleanup;
 118         }
 119
 120         retval = ext2fs_get_pathname_int(fs, gp.parent, dir, maxdepth-1,
 121                                          buf, &parent_name);
 122         if (retval)
 123                 goto cleanup;
 124         if (!ino) {
 125                 *name = parent_name;
 126                 return 0;
 127         }
 128
 129         if (gp.name)
 130                 retval = ext2fs_get_mem(strlen(parent_name)+strlen(gp.name)+2,
 131                                         &ret);
 132         else
 133                 retval = ext2fs_get_mem(strlen(parent_name)+5, &ret);
 134         if (retval)
 135                 goto cleanup;
 136
 137         ret[0] = 0;
 138         if (parent_name[1])
 139                 strcat(ret, parent_name);
 140         strcat(ret, "/");
 141         if (gp.name)
 142                 strcat(ret, gp.name);
 143         else
 144                 strcat(ret, "???");
 145         *name = ret;
 146         retval = 0;
 147
 148 cleanup:
 149         ext2fs_free_mem(&parent_name);
 150         ext2fs_free_mem(&gp.name);
 151         return retval;
 152 }
 153
 154 errcode_t ext2fs_get_pathname(ext2_filsys fs, ext2_ino_t dir, ext2_ino_t ino,
 155                               char **name)
 156 {
 157         char    *buf;
 158         errcode_t       retval;
 159
 160         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 161
 162         retval = ext2fs_get_mem(fs->blocksize, &buf);
 163         if (retval)
 164                 return retval;
 165         if (dir == ino)
 166                 ino = 0;
 167         retval = ext2fs_get_pathname_int(fs, dir, ino, 32, buf, name);
 168         ext2fs_free_mem(&buf);
 169         return retval;
 170
 171 }